Mini Helicopter Could Spray Vineyards

UC Davis engineers demonstrate unmanned aircraft in Napa Valley

by Paul Franson

Professors from the University of California, Davis, are experimenting with the use of unmanned aircraft such as this Yamaha RMAX Type IIG for agricultural use. Currently the Federal Aviation Administration only permits unmanned aircraft for experimental purposes.

Oakville, Calif.—Professors at the University of California, Davis, recently demonstrated an unmanned helicopter that could have numerous vineyard uses including spraying liquid and granular pesticides, seeding cover crops and sensing and implementing precision agriculture.

Professor of agricultural engineering Ken Giles and development engineer Ryan Billing demonstrated the Yamaha RMAX Type IIG aircraft at the university’s Oakville Experimental Vineyard in Napa Valley. The helicopter is in use in Australia but still in experimental stages here.

Giles said, “Our project is to investigate the performance and feasibility of using the unmanned aircraft in high-value crops as an aerial application option—especially in complex terrain or small fields where conventional aircraft may not be suitable or too expensive.”

The helicopter doesn’t compact ground and can be used over wet fields.

Giles said that the spray capacity is low. The liquid sprayer tank holds less than 4 gallons, and the application rates are more typical of aerial (1-5 gallons/acre) than ground application (25-100 gallons/acre.)

Further, Giles noted that the Federal Aviation Administration (FAA) tightly regulates the use of unmanned aircraft, and the aircraft can be used for experimental purposes only.

Steve Markofski of Yamaha Motor Corp. told Wines & Vines that regulatory changes are under way. “Under the FAA Modernization and Reform Act of 2012, Congress included language requiring the FAA to expedite the safe integration of commercial UAS (unmanned aircraft systems) into the national airspace and set a deadline of Sept. 30, 2015, for full integration,” he said. “Yamaha’s goal is to be in position to begin commercial sales of the RMAX by end of September 2015.”

Markofski said the FAA has approved Yamaha’s partnership with UC Davis to conduct experimental flights for data collection and demonstration for agriculture uses such as in the Napa vineyards. The project is receiving financial support from Yamaha.

Regarding the UC Davis researchers’ experiment, Giles said, “We hope from this project to understand how best it could be used in agriculture and forestry. Our initial tests are encouraging in that we saw uniform spray distribution and relatively high productivity in terms of acres per hour.”

He will be continuing the tests as the season progresses.

RMAX Type II G Specifications

• The unit’s body is 2.75 meters (9 feet) long or 3.63 meters (12 feet) including the main rotor (3.13 meters/10.27 feet.)

• It is 1.08 meters (3.5 feet) high and 0.72 meters (2.4 feet) wide.

• The load capacity is 28kg (62 pounds.)

The practical range (visual range) up to 400 meters (1,300 feet.)

• The engine is a two-stroke, horizontally opposed 2-cylinder engine displacing 246 cc. It puts out 15.4 kW (20.6 hp) and starts with an electric starter.

• The liquid sprayer cassette tank capacity is 8 liters (2.1 gallons) in each of two tanks.

• The granular sprayer hopper holds 13 liters (3.4 gallons) in each of two tanks.

• The performance may vary depending on environmental conditions, such as the temperature, humidity, and altitude.

An unmanned helicopterThe RMAX Type II G is a remote-controlled helicopter equipped with a high-performance global positioning system (GPS) combined with the Yamaha attitude control system (YACS) to make operation simple.

The YACS-G mechanism incorporates a support system that controls the rudders to provide flight stability, combined with a high-performance GPS that detects the speed of the helicopter in back and forth, left and right, and up and down directions. It permits easy and precise control for speed and hovering.

The helicopter keeps speed constant if the position of the throttle stick is kept steady. It automatically slows down when the throttle stick is returned to the neutral position, bringing the helicopter to a hover.

The RMAX Type II G incorporates safety features such as a warning system if flying speed during spraying exceeds 20 km per hour and a warning period upon startup.

The main rotor will come to a stop within approximately 20 seconds, with the rotor brake used after the engine is stopped. In case of radio interference, the helicopter will slow automatically and move downward. In case of GPS signal interruption, GPS control of the helicopter will stop, and the helicopter will go into the preselected flight mode.

The helicopter can be used with both liquid and granular tanks.

Standard dispersal width (7.5 meters or 24.6 feet) can be

adjusted to match flying speed.

The unit weighs 100kg (220 pounds) and has wheels on the landing gear, allowing a single operator to move the helicopter. Two people can load it, and training is provided.

So far, Yamaha hasn’t been talking about price. It is looking at a business model where the aircraft would be leased to a contractor who would provide service.

Yamaha representative Markofski said Yamaha couldn’t give a price estimate for the RMAX until the FAA releases specifications for compliance. “As we move closer to 2015, those requirements will become clearer,” he said. You can reach Markofski by email.